DE 33 45 511 C2 discloses an apparatus for limiting a convective heat transfer to a thermostat head from a fluid passing through a valve. In order to limit the convective heat transfer between the valve and the thermostat head an annular disc is provided between the valve and the thermostat head which deflects heated air away from the thermostat head.
From U.S. Pat. No. 6,427,712 B1 an actuator for controlling an anti-freeze plug for draining a condensate collector pan through a drain hole when the ambient temperature approaches freezing is known. A shape memory alloy (SMA) actuator which responds to changes in ambient temperature in which a coiled SMA spring is provided is disclosed.
DE 10 2008 018 639 A1 teaches a thermostatic regulation device in which an actuating member depending on an ambient temperature is formed of a shape memory alloy. This element replaces a bellows usually present for actuating a valve element depending on the ambient temperature of a thermostat head.
DE 10 2008 063 534 A1 teaches a spring element formed of a shape memory alloy which depends on a temperature of an electrically controlled heating element.
It is a known problem in heat exchanger thermostats that temperature depending actuating means for actuating a valve depending on an ambient temperature of the thermostat head are influenced by a temperature of a fluid controlled by said valve. Thus, the temperature depending actuating means may actuate the valve to reduce a fluid flow before the desired ambient temperature is actually reached. Because of that the temperature of, for example, a room may be inadequately low.